Interesting point. I have an external amp in the trunk along with a CD player and an after-market stereo + alarm that I have switched off, but wired into the ign. circuit anyway.
I suppose these external amps are a major source of drain while the car is running and the stereo is on. I would hope that the external amp is not always hot like brake lights.
I need to explore this as I have a current drain issue - losing approx .001 volts every hr. or so.
Granted the battery is getting old - it's now 3.5 yrs. old, but this issue has been with me for quite awhile, even with a fresh battery.
Pulling the factory fuses under the hood doesn't dim a 12 volt test light connected to a disconnected battery grnd. strap.
It could be that it takes less current than I realize to activate a 12 volt test light. Need to go ahead and use the amp scale on my VOM to test for actual draw.
I've always suspected the alarm, but I may be looking in the wrong direction.
Thanks for the tip.